The APC’s blueprint for silicon photonics

The Advanced Photonics Coalition (APC) wants to smooth the path for silicon photonics to become a high-volume manufacturing technology.

The organisation is talking to companies to tackle issues whose solutions will benefit the photonics technology. The Advanced Photonics Coalition wants to act as an industry catalyst to prove technologies and reduce the risk associated with their development, says Jeffery Maki, Distinguished Engineer at Juniper Networks and a member of the Advanced Photonics Coalition’s board.


The Advanced Photonics Coalition was unveiled at the Photonic-Enabled Cloud Computing (PECC) Industry Summit jointly held with Optica last October. The Coalition was formerly known as the Coalition for On-Board Optics (COBO), an industry initiative led by Microsoft. Microsoft wanted a standard for on-board optics, until then it was a proprietary technology. At the time, on-board optics was seen as an important stepping stone between pluggable optical modules and their ultimate successor, co-packaged optics. After years of work developing specifications and products, Microsoft chose not to adopt on-board optics in its data centres. Although COBO added other work activities, such as co-packaged optics, the organisation lost momentum and members. Maki stresses that COBO always intended to tackle other work besides its on-board optics starting point. Now, this is the Advanced Photonics Coalition’s goal: to have a broad remit to create working groups to address a range of issues.

Tackling technologies

Many standards organisations publish specifications but leave the implementation technologies to their member companies. In contrast, the Advanced Photonics Coalition is taking a technology focus. It wants to remove hurdles associated with silicon photonics to ease its adoption.

“We see the artificial intelligence and machine learning opportunities growing, both in software and hardware,” says Maki. “We see a need in the coming years for more hardware and innovative solutions, especially in power, latency, and interconnects.”

Work Groups

In the past, systems vendors like Cisco or Juniper drove industry initiatives, and other companies fell in line. More recently, it was the hyperscalers that took on the role.

There is less of that now, says Maki: “We have a lot of companies with technologies and good ideas, but there is not a strong leadership.”

The Advanced Photonics Coalition wants to fill that void and address companies’ common concerns in critical areas. “Key customers will then see the value of, and be able to access, that standard or technology that’s then fostered,” says Maki.

The Advanced Photonics Coalition has yet to announce new working groups but it expects to do so in 2024.

One area of interest is silicon photonics foundries and their process design kits (PDKs). Each foundry has a PDK, made up of tools, models, and documentation, to help engineers with the design and manufacture of photonic integrated devices.

“A starting point might be support for more than one foundry in a multi-foundry PDK,” says Maki. “Perhaps a menu item to select the desired foundry where more than one foundry has been verified to support.”

Silicon photonics has long been promoted as a high-volume manufacturing technology for the optical industry. “But it is not if it has been siloed into separate efforts such that there is not that common volume,” says Maki.

Such a PDK effort would identify gaps that each foundry would need to fill. “The point is to provide for more than one foundry to be able to produce the item,” he says.

A company is also talking to the Advanced Photonics Coalition about co-packaged optics. The company has developed an advanced co-packaged optics solution, but it is proprietary.

“Even with a proprietary offering, one can make changes to improve market acceptance,” says Maki. The aim is to identify the areas of greatest contention and remedy them first, for example, the external laser source. “Opening that up to other suppliers through standards adoption, existing or new, is one possibility,” he says.

The Advanced Photonics Coalition is also exploring optical interconnecting definitions with companies. “How we do fibre-attached to silicon photonics, there’s a desire that there is standardisation to open up the market more,” says Maki. “That’s more surgical but still valuable.”

And there are discussions about a working group to address co-packaged optics for the radio access network (RAN). Ericsson is one company interested in co-packaged optics for the RAN. Another working group being discussed could tackle optical backplanes.

Maki says there are opportunities here to benefit the industry.

“Companies should understand that nothing is slowing them down or blocking them from doing something other than their ingenuity or their own time,” he says.


COBO had 50 members earlier in 2023. Now, the membership listed on the website has dropped to 39 and the number could further dip; companies that joined for COBO may still decide to leave.

At the time of writing, an new as yet unannounced member has joined the Advanced Photonics Coalition, taking the membership to 40.

“Some of those companies that left, we think they will return once we get the working groups formed,” says Maki, who remains confident that the organisation will play an important industry role.

“Every time I have a conversation with a company about the status of the market and the needs that they see for the coming years, there’s good alignment amongst multiple companies,” he says.

There is an opportunity for an organisation to focus on the implementation aspects and the various technology platforms and bring more harmony to them, something other standards organisations don’t do, says Maki.